Adjustable vane windmills

ABSTRACT

A system of rotatably and pivotally mounted radially extended bent supports for radially extending windmill rotor vanes in combination with axially movable radially extended control struts connected to the vanes with semi-automatic and automatic torque and other sensing and servo units provide automatic adjustment of the windmill vanes relative to their axes of rotation to produce mechanical output at constant torque or at constant speed or electrical quantities dependent thereon.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation in part application of my patent application Ser.No. 874,222, filed Feb. 1, 1978, now U.S. Pat. No. 4,183,715, issuedJan. 15, 1980.

THE FIELD OF THE INVENTION

The field of art to which this invention pertains is windmills.

BACKGROUND OF THE INVENTION

The varying qualities of the wind have limited the suitability of windpower for applications where output of constant speed or torque, as inelectrical generation, is desired. Notwithstanding the long history ofhuman experience with windmills no simple, yet automatically orself-adjusting wind energy conversion apparatus has been heretoforeavailable to automatically provide constant speed or torque output atreadily adjusted values from input based on wind power.

SUMMARY OF THE INVENTION

Radially extending windmill vanes are supported for rotation about oneaxis perpendicular to their length and for pivotal motion about anotheraxis parallel to their length. For such purpose each of these vanes ispivotally mounted on one straight portion of a rigid bent beam andanother straight portion--at an angle to the first portion--of each beamis rotatably and pivotally supported on a rotating hub. The orientationof each of the vanes relative to their pivotal axis of movement on theportion of the bent beam to which the vane is attached is fixed by arigid strut pivotally attached to that vane at one end of the strut; theother end of that strut is connected to a rotatable shaft which is fixedto the hub and extends from the hub along the axis of rotation of thehub and the beams supported thereon. The distance from the rotating hubto the point of attachment of each strut to the shaft is adjustable.Adjustment of the position of the point of attachment of the shaft tothe struts serves to adjust and hold each vane at variable orientationsrelative to the axis of rotation of the vanes and beams and relative tothe pivotal axes of the vanes on the beams. Such orientation determiningapparatus is responsive to conditions such as torque applied to ordesired from the rotating vanes and/or speed desired from such rotatingvanes.

A synchronizing assembly is provided to improve maintenance of equalityof angle of all vane assemblies to the axis of rotation of the vanes. Avariety of assemblies for positioning of the vanes control shaft aredisclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side and top oblique view of an apparatus according to thisinvention.

FIG. 2 is a slightly oblique end view along the direction of arrow 2A ofFIG. 1 and showing the blades in their run position.

FIG. 3 is a perspective view showing in full lines the rotor blades intheir run position, and showing also, in dashed lines, one blade (31) inits feathered position.

FIG. 4 is a central vertical longitudinal diagrammatic section view ofthe rotor control assembly of apparatus of FIG. 1 and related partsoperatively connected thereto.

FIG. 5 is an end view of the rear of hub 30 and related parts.

FIG. 6 is a vertical longitudinal diagrammatic section of parts of theembodiment of the apparatus which parts are located in zone 6A of FIG.3.

FIG. 7 is a diagrammatic vertical sectional view of parts of the vanecontrol assembly according to this invention shown in FIGS. 3 and 6.

FIG. 8 is a diagrammatic view of portions of another embodiment ofoperating apparatus.

FIG. 9 shows a portion of the apparatus 20 in a position of its parts atwhich position blade 31 extends vertically downward from hub 30.

FIG. 10 is a diagrammatic top view along direction of arrow 10A of FIGS.2 and 3 and, also along the horizontal transverse section 10B--10B ofFIG. 2 to illustrate sequential positions of a rotor blade 31 andrelated parts connected thereto during operation of apparatuses of FIGS.1-9.

FIG. 11 is a perspective diagrammatic view of joint 96 in zone 11A ofFIG. 3 showing details of a strut-vane connector in the run mode of thevane or rotor blade.

FIG. 12 is a perspective diagrammatic view of joint 96 in zone 12A ofFIGS. 3 and 10 showing the strut-vane connector in a more featheredposition than in FIG. 11.

FIG. 13 is a diagrammatic perspective view of the strut-collar connector41 in the run mode of the vane to which strut 34 is attached.

FIG. 14 is a perspective diagrammatic view of another form of strut-vaneconnector.

FIG. 15 is an overall side and top oblique view of another apparatus,226, according to this invention comprising synchronizing apparatus 222and control assembly 224.

FIG. 16 is an overall end view along the direction of arrow 16A of FIG.15 and showing the blades in the run position of apparatus 226.

FIG. 17 is a perspective view showing in full lines the rotor blades andsynchronizing assembly in the run position thereof, and showing also, indashed lines, one blade in its feathered position for apparatus 26 andsynchronizing assembly 22, which combination is apparatus 29.

FIG. 18 is a rear end view of the hub 30 and related parts of thesynchronization assembly 222 as seen along direction of arrow 18A ofFIG. 22 and section 18A--18A of FIG. 19.

FIG. 19 is a vertical longitudinal diagrammatic sectional and side viewof parts of embodiment 29 of apparatus, which parts are located in zone19A of FIG. 17.

FIG. 20 is a diagrammatic top view along direction of arrow 20A of FIGS.16 and 17 and also along the horizontal transverse section 20B--20B ofFIG. 16 to illustrate sequential positions of rotor blades and relatedparts connected thereto including the synchronization assembly 222during operation of apparatuses of FIGS. 15-22.

FIG. 21 shows a portion of the apparatus 27, the apparatus 20 plus thesynchronization assembly 222, in the position of its parts at whichposition blade 31 extends vertically downward from hub 30.

FIG. 22 is a central vertical longitudinal diagrammatic sectional viewof the rotor control assembly 224 of apparatus 226 of FIG. 15 andrelated parts operatively connected thereto.

FIG. 23 is a diagram showing relations of subassemblies used with thesensor control assembly 305.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The apparatus 20 comprises a frame assembly 21 and a rotor and controlassembly 22. The rotor and control assembly 22 is composed of a rotorassembly 23 and a control assembly 24.

The rotor and control assembly 22 is rotatably supported on the frameassembly 21. The frame assembly 21 sets on the ground 25 and issupported thereby.

The apparatuses disclosed herein are modifications and improvements ofthe apparatus 20 as below set out.

(1) Apparatus 20 is shown in FIGS. 1, 2, 4, 5, and 9-14.

(2) Apparatus 26, shown in FIGS. 3, 6, and 7 comprises a modification ofthe control assembly 24 in apparatus 20.

(3) Apparatus 28, shown in FIG. 8 comprises another modification ofcontrol assembly 24 of apparatus 20.

(4) Apparatus 226, shown in FIGS. 15 and 22, comprises changes in therotor assembly and in the control assembly of apparatus 20. Apparatus226 comprises the apparatus 20 plus synchronization assembly 222 and acontrol assembly 224.

(5) Apparatus 27, shown in FIG. 21, comprises changes in the rotorassembly 22 of apparatus 20 by inclusion of synchronization assembly222.

(6) Apparatus 29, shown in FIGS. 17 and 19, comprises changes in therotor assembly of apparatus 26 by including the synchronization assembly222 in the rotor assembly 22. The synchronization assembly, which iscommon to several apparatuses, is shown in FIGS. 16, 18 and 20.

The rotor assembly 23 comprises a hub 30, rotor blades 31-33, struts34-36, a blade control shaft 38 and a shaft support sleeve 39, as majorcomponents. The rotor blades 31, 32 and 33 are rotatably supported onthe hub 30.

The hub 30 is supported on the shaft support sleeve 39 and the sleeve 39is supported on the control assembly 24.

Sleeve 39 is rotatably supported on the shell of assembly 24 in bearingsas 161 and 162. Shaft 38 is moved along the length of sleeve 39 by partsof assembly 24. The hub 30 comprises a rigid plate 170 firmly fixed tosleeve 39 and spar shaft journal bearings 171, 172 and 173 and sparshaft seats 174, 175 and 176 for straight spar shaft portions 71, 72 and73, respectively. The bearings 171-173 pivotally hold the spar shaftportions 71, 72 and 73 in a radially symmetrical and tangentiallyextending array as shown in FIGS. 2 and 3 and 5. Shaft 38 is rigid andstraight and supported by rigid cylindrical sleeve 39 for longitudinalmotion along the length of hollow sleeve 39 and is co-axial with sleeve39.

Collar 40 is a rigid annulus or ring and is firmly fixed to shaft 38 atits rear end and comprises and supports three universal strut-collarjoints, 41, 42 and 43. Rigid struts 34-36 extend from universalstrut-vane joints 96, 97 and 98 on the blades 31, 32 and 33 respectivelyto joints 41, 42 and 43. Joints 41, 42 and 43 respectively pivotallyjoin the central end of each of struts 34, 35 and 36 to the collar 40and are equispaced around the collar 40.

Each of the rotor blades or vanes 31, 32 and 33 comprises a rigid bladeframe 51, 52 and 53 respectively and a rigid vane spar 61, 62 and 63respectively. Each frame as 51 is like the other frames 52 and 53 andeach of the spars is like the other spars.

Each spar 61, 62 and 63 has a straight part 71, 72 and 73 and a bentportion 81, 82 and 83 respectively. The bent and the straight portionsare joined at bends 91, 92 and 93 respectively for each of the spars 71,72 and 73. Each of the straight portions is rotatably supported in hub30 at journals 171-173 and on supports 174-176 as shown in FIGS. 3 and5. Each of the straight parts of each of the shafts 71, 72 and 73 isalike and extends in a plane at 84° to the axis of the shaft 38 andsleeve 39. Such planes extend downwardly and windwardly (rightwards asshown in FIGS. 1, 4 and 6) and in a clockwise (as shown in FIGS. 2, 3and 5) direction.

The peripheral portion 81, 82 and 83 of each spar is alike and is a partof and firmly attached to a frame as 51, 52 and 53 of the correspondingblade. Each of the blades 31, 32 and 33 have the same structure;accordingly the description given for blade 31 applies to the otherblades or vanes.

Each rotor blade frame as 51 has a trailing edge 55 and a leading edge56. Each frame as 51 is formed of several rigid transversely extendingribs 57, 58 and 59 and parallel rigid longitudinal members as 66, 67 and69 firmly joined together and arrayed as in FIGS. 2 and 3 and covered bya firm smooth imperforate plastic, wood, metal or cloth sheet as 76, 77and 78 respectively so as to form an effective airfoil.

On each blade or vane, as 31, 32 and 33, its cover (76, 77 or 78) formsa front blade or vane windward surface as 131, 132 and 133 respectivelyand a rear blade or vane surface, as 134 on rotor blade 31, which rearsurface is located on the opposite side of the blade from the frontsurface as 131. The position of surface 131 of the blade 31 is shown as136 in the shifted position of blade 31 shown as 333 in FIG. 10.

In FIG. 2 end portions of covers 77 and 78 are broken away so that theframes 52 and 53 may be shown. In FIG. 3 the cover is shown as removedfrom blade 31 so that the structure of the frame 51 may be shown.

Each of the spars as 61, 62 and 63 is rotatably supported at itsportions 71, 72 and 73 respectively in the hub 30 as shown in FIGS. 2, 3and 5. Movement of the control shaft 38 and collar 40 forward along thelength of sleeve 39 from a position as 40 to position 342 as shown inFIGS. 3 and 10 causes a rotation of each of the rotor blades as 31around the axis of the straight portion as 71 of the spar as 61 from therun position of such blade frame as shown in FIGS. 3 and 10 to itsfeathered position 333 shown in dashed lines in FIGS. 3 and 10.Intermediate positions as 331 and 332 of the rotor blade 31 are alsoshown in FIG. 10 where position 340 of the collar 40 corresponds to theposition of collar 40 in FIG. 3 while in FIG. 10 position of collar 40is a somewhat more rearwardly moved position of the collar 40 than isshown for collar 40 in FIG. 3.

The path 50 of the blade 31 shown in FIGS. 3 and 10 thus provides notonly for a forward motion of the blade frame (from the left in FIG. 3 tothe right in FIG. 3 and as shown in FIG. 10) but also, a rotation fromthe blade orientation relative to the axis of the shaft 38 (whichorientation is shown in full lines in FIGS. 2 and 3) to the orientationand position shown in dashed lines in the FIGS. 3 and 10, due to therotation of the straight portion 71 of the spar 61 in its journal 171,and a consequent rotation of the bent peripheral spar portion 81 whichis attached to the ribs of the frame of the vane or rotor blade.

The frame assembly 21 comprises a upper platform 101, a middle platform102 and a series of rigid vertical post members as 111-116 firmlyattached thereto. The frame assembly also includes a ring 108 which isfirmly attached by brackets as 117 and 118 to all the vertical postmembers. The vertical members are rigid beams and are firmly attached tothe ground 25 and to the platforms 101 and 102. The upper platform isprovided with a railing 104 for the convenience of operators.

The frame assembly 21 comprises four sets each like 231' and 232', eachset composed of three post members as 111, 112 and 113 for set 231' andmembers 114, 115 and 116 for set 232'; each set is generally V-shapedwith the apex of such set setting in one corner of a square area as 234'on ground 25 and the other end of each of said set firmly attached atits top to the upper platform 101 and, at an intermediate portion to themiddle platform 102 while brackets as 117 and 118 support the ring 108so that the peripheral surface of that ring provides a smooth circularsurface to contact the chain portion 178.

The platform 101 firmly supports a rigid vertically extending pedestal107 on which the rotor and control assembly 22 is mounted for rotationabout a vertical axis of shaft 186. The frame assembly 21 is symmetricalabout a vertical assembly axis. That vertical assembly axis is co-axialwith the central longitudinal axis of the cylindrical pedestal 107.

Generally, the frame assembly 21 provides a support for the rotor andcontrol assembly 22 and a connection from the output of the rotorassembly 22 to a generator 187. Additionally, the frame assemblyprovides a minimum resistance to wind passing therethrough andtherearound by permitting wind to pass through the spaces between thespaced apart beam members as 111-116. Additionally, the frame assembly21 provides a support for the ring 108 which acts as a guide for thesprocket chain 178.

The control assembly 24 comprises, in operative combination, a rigidshell subassembly 140, a control shaft subassembly 150 and a powertakeoff subassembly 180.

The shell subassembly 140 comprises rigid rear casting 141, a rigidcentral casting 142, a rigid forward end casting 143 and a lower,shoulder, casting 144. These are firmly joined together by bolts as146-148. A rigid cylindrical central sleeve 145 is is firmly attached tothe lower casting 144 and is rotatably located within the pedestal 107.Bearings 161 and 162 fixed in the casing subassembly 140 rotatablysupport both shaft support sleeve 39 within the cavity 149 of the shellsubassembly 140 and the hub exteriorly thereof. Bearings 163 and 164 incasting 143 rotatably support a cylindrical sprocket sleeve 156 withinthe casting 143.

The bolts as 146-149 firmly hold the elements 141-143 of assembly 140together and surround a T-shaped shell assembly cavity 149 within thecastings 141-145, all of which are hollow.

A ring bearing 165 rotatably supports the shell subassembly 140 on thepedestal 107. Bearings 166 and 167 rotatably locate rigid cylindricalsleeve or tube 145 within the cylindrical pedestal 107 and co-axialtherewith. The upper end of tube 145 helps to fixedly locate other partsof the casing subassembly 140 relative to gears 181 and 182.

The lower end of tube or sleeve 145 extends to platform 102 and isrotatably held at that platform by bearings therefor firmly held on orin that platform.

The control shaft subassembly 150 comprises the front portion of thecontrol shaft 38 and the shaft support sleeve 39, a helically groovednut 151, a helically threaded rigid shaft 152, a sprocket sleeve 156,cap 154 and a bearing 168. The nut 151 is firmly fixed to sprocket shellor tube 156 which is rotatably located in bearings 163 and 164 withinthe casting 143. The nut 151 has internal helical threads which matchthe helical threads on the screw shaft 152. Shaft 152 has a slottedcylindrical portion which is smoothly slidably held within the bearing168 held by a rigid key 153, in form of a bolt, within a keyway or slotin shaft 152 to prevent rotation of shaft 152.

The bearing 168 is not a rotating bearing but provides for longitudinalmotion of the shaft 152 along the direction of the axis of the shaft 38.Bearing 168 is firmly located within a shoulder on the casting 143 andthat bearing is co-axial with the hole in the nut 151 and with the shaft152 and with the shaft 38 and sleeve 39.

The cap 154 is C-shaped in section. It has an inturned shoulder 137 andsmoothly seats as well as holds and embraces a cylindrical head 37 ofshaft 38. Head 37 is rigid and has a greater diameter than shaft 38 andthe head 37 is co-axial with and firmly fixed to the rigid shaft 38. Arigid circular sprocket wheel plate 157 is firmly attached to and isco-axial with the rigid cylindrical sprocket shell or sleeve 156 andsupports a flexible steel chain 158 at the lower end of which is locatedweight 159. The chain is located at a horizontal distance from thecenter of tube 145 (which tube 145 is co-axial with the output powershaft 186) as is the periphery of the ring 108. Accordingly, chain 158is readily moved around the frame assembly 21 when (a) the direction ofwind 70 changes and (b) the rotor and control assembly 22 rotates inresponse to such change in wind direction and (c) the top portion ofchain 158 is moved with sprocket wheel 157 and (d) a lower portion 178of that chain 158 attached to weight 159 follows the movement of thesprocket wheel without tangling on the frame 21 because it bears on thesmooth surfaced circular sectioned and shaped ring 108.

The chain 158 has a longer weight bearing portion 178 and a shortertakeup portion 177 and engages the teeth on the sprocket wheel 157. Thelonger portion 178 reaches the weight 159 and is firmly connectedthereto. The shorter length is attached to a rigid wide circular ring179 which loosely surrounds the length 178. A circular rigid hood 160 issupported on casting 143 and closely overhangs chain 158 to preventloosening of such chain on the sprocket wheel 157.

The power takeoff subassembly 180 comprises a bevel gear 181 whichengages another bevel gear 182, and an output power shaft 186 directlyconnected to gear 182 and to a generator 187 on the ground 25. Bevelgear 181 is fixedly and firmly connected to and co-axial with the shaftsupport sleeve 39. The shaft 186 is rotatably supported in the tube 145by bearings 184 and 185.

The rotation of the bevel gears 181 and 182 results from the rotation ofthe sleeve 39 which results in the rotation of the hub 30, which in turnresults from the rotation of the rotor blades 31, 32 and 33, whichrotation in turn is caused by the wind applied to such blade, and causesrotation of the shaft 186.

In start of operation of apparatus 20 the chain 178 is pulled and urgesthe screw shaft 152 to the left and thereby extends the collar 40 andthe shaft 38 towards the maximum extension thereof from the rear end ofsleeve 39, as shown by extreme position of collar 40 at position shownas in FIG. 10. The surfaces 131-133 of the vanes as 31-33 are usually atan angle to the direction of the wind as shown by position 331 for vane31 in FIG. 10 which vane position is that shown in FIGS. 1 and 2 and 3for vanes 31-33. In such position of the vanes the wind 70 causes thevanes 31-33 to rotate clockwise as viewed in FIG. 2; such clockwisedirection is shown by the arrow 75 in FIGS. 2 and 3. While the vanes areurged by the wind moving in the direction 70, as shown in FIGS. 3 and10, to move in a clockwise direction 75 around the central longitudinalaxis of the shafts 38 and 39 each of the vanes as 31 also is urged tomove in a counterclockwise rotary direction 50 about the axis of thestraight portion 71 of the spar 61 to which each such vane is attached.When such vane motion in path 50, as shown in FIG. 10, occurs, it movesthe blade surfaces as 131 towards a feathered position as at position333 in FIGS. 3 and 10. On such motion along path 50 (a) the blades 31-33draw the collar 40 and shaft 38, through the struts 34-36, toward thehub 30 in direction of arrow 90 of FIGS. 4 and 10; as a result (b) thehead 37 of shaft 38 acts against the cap 154 and moves the screw shaft152 forward (to the right as shown in FIGS. 1 and 4) and (c) theengagement of screw 152 and nut 151 rotates the sprocket sleeve 156clockwise as seen in FIG. 2 and shown by arrow 95 in FIG. 4 and (d) thesprocket wheel lifts the chain portion 178 to which the weight 159 isattached. Once the weight is lifted off the ground 25, as shown in FIG.4, the weight 159 tends to turn the sleeve 156 and screw shaft 152counterclockwise as viewed in FIG. 2 and thus opposes further forwardmovement (in direction of arrow 90) of the shaft 152. As the vanerotation speed increases at a fixed position of blades 31-33 it developsa greater tensile force on struts 34-36 and a greater forwardly directedforce (in direction of arrow 90) on shaft 152 and develops a greaterturning force in direction of arrow 95 on sleeve 156 by engagement ofscrew shaft 152 and nut 151 fixed to the sleeve 156.

The weight 159 thus applies a constant torque to fix the orientation ofthe blades to the wind direction. Insofar as the force of weight 159 isthereby overcome (by the turning force in direction of arrow 95) collar40 draws closer to hub 30 and each of the rotor blades as 31 then pivotsthe bent spar portion thereof as 81 about the straight portion as 71 ofthe spar therefor as 61; the surface 131 orientation of the blade as 31then is changed to an orientation or position as 333 in FIGS. 3 and 10,whereat the angle of the blade surface to the direction of the winddecreases; i.e. the blade 31 "feathers". Thereby a steady state ofangular relation of the windward surfaces 131, 132 and 133 of the rotorblades or vanes 31, 32 and 33 respectively is developed for anyparticular wind velocity and torque then opposing such turning of theblades. Thus, as the vane R.P.M. changes the orientation of the bladessurfaces as 131-133 changes between the positions shown for surface 131in FIG. 10 and the position 136 in FIG. 10 for the surface 131 of theblade 31, to automatically provide to the output shaft 186 a constantamount of net torque, set by the value of weight 159 regardless of thewind speed.

The torque required by the electrical generator 187 depends upon thevoltage it generates and the current drawn from that generator so thatthe torque required to turn that generator depends upon the load takenby that generator which may be a variable. Such torque of the generator187 resists motion of the shaft 186 which shaft drives that generator187 and, like weight 159, resists motion of the rotor blades as 31-33and of the hub 30. Accordingly, as force on the collar 40 which wouldtend to provide displacement thereof depends upon the reaction or theback torque developed by the generator 187 such torque needs to beovercome as well as torque provided by the weight 159 beforelongitudinal shift of the screw shaft 152 occurs. Accordingly, thisapparatus 20 automatically provides for a constant output torque atshaft 186 which accommodates and automatically corrects for variation inwind velocity and also generator load. Thus, as the wind velocityincreases the torque is kept contant by a shifting of the orientation ofthe rotor blade surfaces as 131-133. As the load taken by the generatorincreases a greater torque is provided and creates a shifting of theblade orientation relative to the wind so that the torque input into thegenerator stays constant notwithstanding variation load on the generatorand, also, variation in wind velocity.

When the rotor blades pass behind the frame assembly 21 as shown in FIG.9 the air flow velocity falls in its travel in the direction (70) pastassembly 21 towards blade surfaces as, 131 then extending in thedirection generally parallel to the vertical shaft 185 and downward fromshaft 38. Such blade is briefly described as in the "shadow" of thetower or frame assembly 21.

In that position as shown in FIG. 9 the tension in the other rotorblades as 32 and 33 (then not in the "shadow") continues to urge thecollar 40 forward and, also, at that moment in operation the strut 34which is a rigid member, urges the universal hinge joint 96 to which thestrut 34 is attached forwardly and thereby positively maintains theorientation of each of the blades as 31 while it is in the shadow of thetower or frame assembly 21 and so avoids development of vibration andoscillation of the blades because of the wind condition behind the frameassembly. The rigid attachment of each of the struts 34-36 by universaljoints 96 and 97, 98 and 41, 42 and 43 prevents development of suchundesired oscillation.

Each of the pivotal joints 41-43 on the collar 40 is like the joint 41accordingly the description of joint 41 applies to the others. The joint41 comprises a pair of rigid upstanding lugs 124 and 125 which supportone, horizontal, arm of a rigid cross 126. The vertical arms of thatcross 126 are joined to arms as 128 and 129 of a fork 127 and that forkis firmly joined to the rigid strut 34. This provides a readily flexiblejoint yet one that is dimensionally stable.

The universal joints 96-98 are the same in structure according to thedescription of 96 applies to the others. The universal joint 96comprises a rigid arm 191, one end which is attached to the rigid sleeve86 which firmly attaches to the spar portion 81 of the frame 51 of theblade 31. The other end of that rigid arm 191 is attached to a fork 192;the arms 193 and 194 of that fork support one arm of a rigid cross 195.The other arms of that cross 195 are rotatably supported by arms 197 and198 of a fork 196 which is rigidly attached to the strut 34. The strut34 is a rigid arm and the other end of the arm is attached to the fork127 of the joint 41. Accordingly, there is a pivotal connection at thejoints 96 and 41 and at the same time this connection is dimensionallystable so that the strut 34 and its joints serves as a weight orcompression supporting element because the joints 41 and 96 to whichstrut 34 connects serve in combination with strut 34 as a dimensionallystable compression supporting assembly to hold the vane to which strut34 is thereby connected in a fixed spatial relation to the collar 40 aswhen the vane is in the "shadow" of the frame assembly 21 as well asproviding for pivoting of the vane surface as 131 around its support atspar portion 71 in hub 30.

In an alternative embodiment of joint for joint 96 a rigid arm 391(corresponding to arm 191) supports a vertical arm on which a ball for aball joint is located. That ball is engaged by a cap 395 with aspherical cavity therein; that cap is joined by a rigid arm 397 whichattaches firmly to the strut 34 and thereby provides a rigid connectionfrom the joint 41 to the vane 31 which, while dimensionally stable, ispivotal and allows the vane to change position as shown in FIGS. 3 and10; thereby the position of the vanes 31-33 may be closely andaccurately controlled by movement of the collar 40 relative to the rotorblade or vane surface 131.

Embodiment 26 is shown in FIGS. 3, 6 and 7 and is identical to apparatus20 except for the substitution of control assembly 200 in zone 6A ofFIG. 3 for the control assembly 24 in embodiment 20. Embodiment 26comprises the frame assembly 21, the rotor assembly 23 and a controlassembly 200. The rotor assembly 23 is on the same hub 30 as inapparatus 20. In the embodiment 26 as shown in FIGS. 6 and 7 the overallarrangement of a frame assembly as 21, a rotor assembly 22, and acontrol assembly is the same as in the apparatus 20 except that theembodiment 26 has a control assembly 200 that includes a electricalservo mechanism rather than the mechanical torque sensing andautomatically responsive unit 24 used in embodiment 20.

In embodiment 26 a rigid motor shell 201 is rotatably supported forrotation about a horizontal axis by a rear bearing housing 204 and by acentral bearing housing 203 in a rigid outer control assembly casing208. Shell 201 is cylindrical and co-axial with and fixedly attached atits rear end to rotatable sleeve 239 and, thereby, to hub plate 170 and,at its front end, shell 201 is attached to output shaft 202. Shaft 202drives an output bevel gear 182; the shaft 202 is rotatably supported inbearings 261 and 262 which are rigidly held by casing 208. Casing 208 isa rigid cylinder with a horizontal extending axis that is firmlysupported on a rigid support 240; support 240 is fixedly mounted on acasting 144 of assembly 22 and thereby rotatably mounted on the platform101 in the same rotatable manner as the control and rotor assembly 22 ismounted in embodiment 20.

An electrical sensing and control circuit 205 is mounted within thehousing 208 and is operatively connected to a servo motor 212 whichmotor is an electrical driven motor which has a outer stator or shellthat is firmly attached to the internal shell 201 and also has an outputshaft that is firmly attached to the input of a speed reducer 210. Theoutput of the speed reducer is firmly attached to a ball nut screw shaft252, which is a rigid externally threaded shaft like 152 and isrotatably supported in sleeve 239; its threads engage a ball nut 251like 151. Ball nut 251 is firmly attached to the front end of rigidcontrol shaft 238. Shaft 238 has a longitudinally extending ball bearingengaging keyway 255 therein and, also, a recess 256 for movement of therear end of shaft 252 therein. A rigid tubular extension, 249, of sleeve239 is firmly attached to sleeve 239 and has a ball bearing engagingslot 250 therein. Ball bearing balls as 253 located in slot 250 extendinto and engage keyway 255. Thereby shaft 238 is easily movable axiallyby shaft 252 parallel to the length of tube 239 in which it is slidablylocated. Tube 239 is a rigid steel sleeve and is co-axially with andfirmly attached to hub plate 170 (which is the same as plate 170 in hub30). Slip rings 214-217 contact wires connected to circuit 205 andprovide for connection of a power and control source for a motor 212 anddriving of such motor 212 to turn the screw shaft 252 relative to sleeve239 and thereby move the control shaft end and collar 40 toward and awayfrom the plate 170 under control of the sensor unit 206. Floatingbatteries as 188 are provided to be connected to and kept charged by thegenerator 187 for purpose of actuating motor 212 via the sensor circuit205 or other control condition desired. When motor 212 is not turningscrew shaft 252 a brake 211 supported in shell 201 and attached to theinput to speed reducer 210 fixedly positions shaft 252 relative to shell201.

The control shaft 238 has, at its outward end (left in FIG. 7) a spideror collar as 40 with joints 41, 42 and 43 attached to struts 33, 34 and35. The bearings 203 and 204 within the casing 208 on which the entirehousing 201 rotates provides, in combination with the control circuit205, that the position of the rotor blades as 31, 32 and 33 iscontrolled by movement of the arm or shaft 238 within the sleeve 239above described for embodiment 26. Thereby, for instance, the outputvoltage of the generator 187 connects into the sensor assembly 205 andacts therewith to control the motor 212 responsive to the voltage outputthe generator 186 (or 220) provides. Thereby the action of the rotors isresponsive to conditions sensed at the control circuit 205. When voltageoutput of 187 falls below or rises above a certain amount the pitch ofthe rotor blades is controlled by motor 212 for a greater or lesserrotor blade speed (as by increasing or decreasing the distance of thecollar 40 from the plate 170) and so control of pitch by the rotorblades.

Control circuit 205 may also have as input both the wind speed sensed bysensor unit 206 and the speed of the rotation of the shaft and,accordingly, automatically drive motor 212 for an adjustment of theorientation of the blades of assembly 23, as 31, for a predeterminedspeed or for maximum speed as well as for the maximum production oftorque and speed. The apparatus 26 also provides for adjusting the rotorspeed depending upon the torque developed by the rotors. Embodiment 28is shown in FIG. 8. It provides a variation to the combination ofelements in apparatus 26. In embodiment 28 the blade control assembly200 is supported on a rigid housing 244 on which a electrical generator220 also is located. Output shaft 202 above described in embodiment 26directly drives generator 220. Housing 244 is supported on a casting as144 as in embodiments 20 and 26 for rotatable position of the housing244 and generator 220 for rotatably positioning about a vertical axis ona an elevated pedestal. As the housing 220 for electrical powergeneration is located at the top of the tower or frame assembly 21 onlywires, as 246 are required for energy transmission to storage batteries188 at the bottom of frame 21 inasmuch as the mechanical transmissionsfor electrical generation is accomplished at the top of the tower.

In apparatus 20, through the weight 159 attached to the chain 178attached to the sprocket 157, a constant rpm is achieved by the vanes31-33 because the spars 61-63 are tilted (at 84° to axis of shaft 38) aswell as bent so as to cause each of those vanes to rotate about an axis(as 99) which is tranverse to shaft 38 and transverse to the length ofthe vane 31 as the speed of the vanes and the centrifugal force thereonincreases, but due to controls of assembly 23, as the vanes rotate aboutthe axes of spars 71-73 the relative blade angles to the wind decrease,which slows their rotation speed about the axis of shaft 38. For theapparatus 20, at 13 mph windspeed the apparatus will rotate at about 100rpm, slowly increasing in speed with increasing windspeed reachingapproximately 120 rpm in 100 mph winds.

As the pitch of the vanes are thereby varied or feathered, a constantspeed at a variable torque is achieved even though the wind speedvaries. The struts are attached to the vanes 31-33 by joints 96-98 atthe centroid of force thereof and are dynamically balanced. Vibrationloads are readily compensated for according to this invention by runningat preselected rate of rotation. The ability of these apparatuses or as20, 26 and 28 to operate at fixed rpm or fixed range of rpm avoidsvibration problems. The blades are preferably made of aluminum and aretwisted with the angle of surface 131 to the axis of shaft 38 being 2 to4 degrees greater at the central vane surface edge 87 than at radialvane surface edge 88.

The ball screw 152 used in the exemplary embodiments 20 and 26 is astandard model as model R-55 of Rockford Ball Screw Company; it has a1.0 inch lead and has a 1.140 inch root diameter and a 1.50 inch outsidediameter; on nut 151 the ball diameter is 0.343 inch; the ball nut has atotal length of 35/8 inches and the threaded connection between nut andscrew withstands a static load of 32,000 lbs. As shown in FIG. 4, thehelical threads on shaft 152 are sloped upwards and to the right. Theball screw 152 and its nut 151 are shown diagrammatically in verticallongitudinal section in FIG. 4. Ball nut 251, which is substantiallyidentical to ball nut 151, as shown in side view in FIG. 7.

In apparatus 20 the angle at 91 between portions as 71 and 81 of eachspar as 61 is 12 to 14 degrees (12°-14°).

The length of the blade surfaces as 131 from the central edge 87 to theradial edge 88 thereof will range from 12 to 18 feet with all of thevane surfaces 131, 132 and 133 of the same size and shape and positionrelative to hub 30 in a preferred embodiment. Also, the attachment ofjoints 96-98 to each vane as 31-33 is between 50% and 66% of thedistance from central edge 87 to radial edge 88 of each of the rear vanesurfaces as 134 when the edges as 55 and 56 of the blades are parallelto each other (as shown in the drawings).

An extensible boot extends from rear end of support sleeve 39 to shaft38 to cover shaft 38 for its maximum distance of travel during operationor may extend from rear end of support sleeve 39 to collar 40, as shownin FIG. 4.

The synchronizing assembly 222 promotes the synchronization of therotation of the rotor assemblies 31-33. The synchronizing assembly 222comprises a slider collar assembly 280 and a set of linkage assemblies271, 272 and 273. The collar slider assembly comprises a rigidcylindrical sleeve 283 which forms a smooth sliding fit on the controlshaft, as 338, of the rotor assembly with which assembly 222 is used.The same synchronizing assembly 222 is used on the rotor assemblies inapparatuses 20, 26, 27 and 29 as well as on assembly 226 for which thisdescription is given.

The sliding collar or sleeve 283 has firmly attached thereto in radiallyequispaced array a set of clevises 284, 285 and 286. Each clevis as 284is formed of a pair of rigid clevis arms as 287 and 288 alike in sizeand shape.

Synchrolinkage assembly 271 is applied to spar 71 of rotor bladeassembly 31; linkage assemblies 272 and 273 are applied to the spars 72and 73 of the rotor blade assemblies 32 and 33 respectively. Each of thelinkage assemblies is made of components that have the same size andshape.

The synchrolinkage assembly 271 comprises a central slider-linkage arm294, a ball joint 295 and a radial synchrolinkage arm 296, and a sparcollar 297. The central arm 294 is pivotally fixed at one end at a pin298 to the clevis arms as 287 and 288. The arm 294 is rigid and straightand is connected at its radial end distant from the pivot pin 298 to aball joint 295. The ball joint firmly connects to one, outer, end of theradial arm 296; that arm 296 is rigid and connects at its other innerend to a rigid collar 297 which is firmly fixed to the spar 71. The arm296 extends at right angles to the spar 71 and, in the run position ofthe blade to which the spar is attached, i.e., as shown in FIG. 20, withthe surface of the blade, makes the greatest angle with the axis of theshaft 338 (or 39 in embodiment 20 and 26). On feathering of the blade asshown in FIG. 20 the spar 71 rotates and the arm 296, being fixed tothat spar by the rigid collar 297, rotates correspondingly and thecollar assembly 280 is moved rearwardly (downward as shown in FIG. 20and to the left as shown in FIG. 17). The linkage assembly 272 iscomposed of a central arm 374, ball joint 375, a radial arm 376 and acollar 377 corresponding to the arm 294, joint 295, arm 296, and collar297 of assembly 271. The linkage assembly 273 is formed of arm 494,joint 495, radial arm 496 and collar 497 corresponding to arm 294, joint295, arm 296, and collar 297 of the synchrolinkage assembly 271. Thearms 294, 374 and 494 are all of the same length and size and are rigid;the arms 296, 374 and 496 are all the same size and length and rigidityand the distance from the pins of clevises 284, 285 and 286 to thejoints 295, 375 and 495 are the same and the center to center distancesfrom the center of joints 295, 375 and 495 to the center of the collarstherefor 297, 377 and 497 respectively, are the same. Accordinglymovement of an assembly as 271 caused by rotation of one of the spars as71 which causes a given longitudinal motion of the collar 283 along theshaft as 338 (or 39) therein provides that the same amount of rotationis applied through that linkage assembly 222 to the other spars as 72and 73. Thereby all of the spars and the blades attached to those sparsundergo the same amount of rotation relative to the axis of the shaft338 (or sleeve 39 in embodiments 20 and 26) and compensates forflexibility of spars and of the struts as 34-36 and prevents variationof angle of the rotor blades or vanes 31-33 because of dimensionalchanges concomitant on such flexibility and so improves the smoothnessof operation of the rotor assembly 23. In FIG. 21, the synchronizationassembly 222 is shown added to the rotor assembly 22 of apparatusembodiment 20; that combination of apparatus is referred to as apparatusembodiment 27. The addition of the synchronization assembly 222 to rotorassembly 22 of apparatus embodiment is shown in FIGS. 17 and 19; thatcombination of apparatus is apparatus embodiment 29.

The apparatus embodiment 226 is shown in FIGS. 15 and 22 and isidentical to apparatus 20 except for the substitution of controlassembly 224 in zone 19A of FIG. 17 for the control assembly 24 inembodiment 20 and incorporation of synchronization assembly 222 in rotorassembly 23. Embodiment 226 comprises the frame assembly 21, the rotorassembly 23 and a control assembly 224. The rotor assembly 23 is on thesame hub 30 as in apparatus 20 with addition of synchronization assembly222. In the embodiment as 226 shown in FIGS. 15 and 22 the overallarrangement of a frame assembly as 21, a rotor assembly 23, and acontrol assembly is the same as in the apparatus 20 except that theembodiment 226 has a control assembly 300 that includes an electricalservo mechanism within control assembly casing 308 rather than themechanical torque sensing and automatically responsive unit 24 used inembodiment 20 and rather than the screw mechanism outside of the housing208 in embodiment 26.

The control assembly 224 comprises, in operative combination, a rigidshell assembly 308, a blade control shaft 338, a power takeoff assembly380 and a shaft actuator assembly 350. The shell assembly 308 comprisesa rigid rear casing portion 344, a rigid central casing portion 345, arigid front casing portion 346 and a lower base casing portion 347.These are firmly joined together (as by bolts as 348). Shell assembly348 surrounds a T-shaped shell assembly cavity 382. A ring bearing 165rotatably supports the shell assembly 308 on the pedestal 107 of theframe assembly or tower 21.

Lower bearings 360 and 361 fixed in the casing portion 347 rotatablysupport output shaft 381 and lower bevel gear 282 within the cavity 382of the shell assembly. Bearings 463 and 464 in casing portion 346rotatably support a rigid cylindrical sleeve 339. Bearings 304 and 303rotatably support the shaft 302 of a pinion gear 315.

Blade control shaft 338 comprises a rigid cylindrical shaft portion 358an expanded head 337 (like head 37 in FIG. 4) and a cavity 356.

Blade control shaft 338 is slidably located in sleeve 339 to movelongitudinally thereof, i.e., parallel to the length of axis of rigidactuator shaft 338, and to rotate therein. The rear (left as in FIG. 22)end of shaft 338 is a solid shaft fixedly connected to the collar 40 andslidably supports the slidable collar assembly 280 near hub 30.

The power take-off assembly 380 comprises the hub plate 170, a rigidsleeve 339, pinion gears 316 and 315, the shaft 302 for one pinion gear,bevel gears 281 and 282 and an output connector 383.

The turning power which the vane assemblies produce through action ofthe wind thereon turns the plate 170: the sleeve 339 is firmly attachedthereto and to the gear 316. The sleeve 339 is firmly and rotatably heldin the bearings 363 and 364. The gear 316 drives the gear 315 which itengages. Gear 315 is supported on and firmly attached to the rigid shaft302; that shaft is rotatably supported on bearings 303 and 304 and isfirmly attached to a bevel gear 281 which drives the bevel gear 282;that bevel gear 282 drives the shaft 381 which via coupling connector383, drives the shaft 186 and generator 187.

The shaft actuator assembly 350 is attached to and controls the movementof the blade control shaft 338. The shaft actuator subassembly 350comprises a helically grooved nut 351, a helically threaded shaft 352, acap 354 (like cap 154) and a cap guide assembly 367.

The nut 351 is like nut 151 in FIG. 4 and has internal helical threadswhich match the helical threads on shaft 352, which is a rigidexternally threaded shaft like 152 and is rotatably supported on cap354; its threads engage a nut 351. Cap guide assembly 367 comprisesbrackets 362 and 363, a rigid control rod 364, a control block 365 and aguide plate 366.

The cap 354 is C-shaped in section. It has an inturned shoulder 337 andsmoothly seats as well as holds and embraces an enlarged cylindricalhead 337 of shaft 338. Head 337 is rigid and has a greater diameter thanshaft 388 and the head 337 is co-axial with and firmly fixed to therigid shaft 338.

Ball nut 251 is firmly attached to the rear end of rigid control cap354. Shaft 338 has a longitudinally extending recess 356 for movement ofthe rear end of shaft 352 therein. Thereby shaft 338 is controllablymovable axially by shaft 352 parallel to the length of tube 339 in whichit is slidably located. Tube 339 is a rigid steel sleeve and isco-axially with and firmly attached to hub plate 170 (which is the sameas plate 70 in hub 30) and provides for longitudinal motion of the shaft338 along the direction of the axis of the shaft 338. Bearing 339 isfirmly located within a rigid wall in casing 341 and that bearing iscoaxial with the hole in the nut 351 and with the shaft 352 and with theshaft 338.

The rigid guide plate 366 is firmly attached to the cap 354 and the capis firmly attached to the grooved nut 351. The guide plate is firmlyattached to the block 365 which is a rigid block and smoothly andslidably fits on a rigid guide rod 364. The guide rod 364 is firmly heldby the brackets 362 and 363 to the casing 308. Thereby, on rotation ofthe helical shaft 352 the cap 354 moves forward (to the right as in FIG.22) or rearwardly (to the left as in FIG. 22). The head 337 freelyrotates within the cap 354 and is movable longitudinally of the helicalshaft 352 on turning of the shaft 352. The firm location of the helicalshaft 352 within the bearing 301, which bearing is firmly attached tothe casing 308 by a support therefor as 357, and the rotatable yet firmattachment of the C-sectioned cap 354 and bearing 353 to shaft head 337and the location of the shaft 338 within the bearing 339 within thecasing portion 346 provide that the shaft 338 is movable longitudinallyalong the axis of that shaft depending upon the rotation of the threadedshaft 352, as the block 365 attachment to the rod 364 prevents rotationof the cap 354 or bearing 351.

An electrical sensing and control circuit 305 is mounted within thehousing 308 and is operatively connected to a servo motor 312 whichmotor is an electrical driven motor which has an outer stator or shellthat is firmly attached to the internal shell 308 and also has an outputshaft that is firmly attached to the input of a speed reducer 310. Theoutput of the speed reducer is firmly attached to ball nut screw shaft352 so helical shaft 352 is moved by motor 312 operating through speedreducer 310 and a clutch 315. A brake 311 serves to hold shaft 352 inposition when it is not desired to be moved. The motor 312 and the brake311 are under control of the sensor and control circuit 305. In theoverall, circuit 305 provides for connection of a power and controlsource for motor 312 and driving of such motor 312 to turn the screwshaft 352 relative to ball nut 351 and thereby move the control shaft338 end and collar 40 toward or away from the plate 170.

The control shaft 338 has, at its outward end (left in FIG. 22) a spideror collar as 40 with joints 41, 42, and 43 attached to struts 33, 34 and35 as in assembly 20 and 26. Accordingly, the position of the rotorblades as 31, 32 and 33 is controlled by movement of the arm or shaft338 within the sleeve 339 along the length of shaft 338.

When motor 312 is not turning screw shaft 351 a brake 311 supported inshell 308 and attached to the shaft of motor 312 serves to fixedlyposition shaft 352.

Floating batteries as 188 are provided and connected to and kept chargedby the generator 187 for purpose of actuating motor 312 via the sensorunit 305.

The sensor and control assembly 305 comprises, as diagrammatically shownin FIG. 23, in operative combination, a wind speed sensor 36, arevolutions per minute sensor 307, a strain gauge assembly 309, avoltage sensor 316, a phase angle sensor 317, vibration sensor 318, afactor memory and comparator assembly circuit 320, a power input 319, alogic circuit 331, a motor forward and reverse relay 321, and a brakerelay 322.

The wind speed sensor is mounted on casing 308 to provide to the circuit320 a measure of the wind speed. The r.p.m. sensor 307 reads the r.p.m.of the shaft 338 and thereby determines the r.p.m. of the rotor bladeassembly 23 and transmits such information to the memory and comparatorassembly circuit. The strain gauge assembly 309 measures the torqueapplied by the rotor assembly and transmits such information to thememory and comparator circuit 320; the power input 319 is connected to afloating battery 188 or otherwise, as by a Zener diode circuit, providesa fixed voltage to the memory and comparator circuit 320.

The memory and comparator circuit 320 comprises a plurality of sectionsas 325-330, each comprising a memory and comparison circuit or unit intowhich information on a particular parameter, such as wind velocity (inunit 325), r.p.m. (in unit 326) strain gauge resistance (in unit 327),voltmeter reading (in unit 328), vibration presence (in unit 329) orphase angle (in unit 330) are respectively stored. These units 325-330may be electromechanical units or integrated circuit units or packages.The memory thereof may be a simple mechanical setting of tension in thespring of an electromagnetic relay by adjustment of a screw therefor orthe memory may be provided by integrated circuits of the read onlymemory type after programming. The comparison portion of each of thecircuit units 325-330 compares the incoming signal with the input fromthe memory portion and provides an output repesentative of thedifference between such actual input and the desired condition of whichsuch measurement is made.

The logic circuit 334 for the motor forward and reverse relay 322 isactuated by the memory and comparator assembly circuit 320 and ispowered by input 319 and drives the motor 312 (a) forward or (b)backward or (c) not at all depending upon the signals supplied thereto.When the motor relay 321 is not actuated to provide forward or reverseaction to the motor 312, the circuit 320 inhibits application of powerto relay 321 for the solenoid in the brake 311, and the brake 311 locksthe shaft 352 in position.

In operation of the control assembly 305 the output torque developed bythe rotor assembly 23 may be sensed by a strain gauge assembly 309 onshaft 302. The torque may also be measured by measurement of the outputvoltage of generator 187 (driven by shaft 186 and power take offassembly 380) if generator 187 is a direct current generator; the outputtorque may also, alternatively be measured at phase angle sensor 317 bythe phase angle developed when the generator 187 is an alternatingcurrent generator as well as by the phase angle at the generator outputwhen the generator 187 is connected to an a.c. power line, 323.

At a given wind velocity the torque output from assembly 23 isproportionate to the r.p.m. of assembly 23 at a particular angle of theblades to the axis of shaft 338 (or 38). Accordingly the torque may bemeasured at sensor 307 by measurement of the r.p.m. rotor assembly 23when the wind velocity is known. In operation the torque reading fromsensor 309 or from r.p.m. sensor 307 and wind velocity sensor 306 may befed into a memory and comparator circuit 320; the circuit 320 in turnfeeds a proportionate or representative output signal into the motor andbrake relays 322 and 321 respectively representative of thedetermination in the comparator circuit of whether more or less torqueor speed is required.

The motor relay 321 passes power to the motor 312 if a change in settingof the blade assembly 23 is needed; if no change is needed the brake 311seizes the shaft 352; if a change is needed a solenoid is actuated bycircuit 305 and releases the brake; that control circuit 305concurrently energizes the motor 312 to move the shaft 352 clockwise orcounterclockwise depending upon the movement of shaft as 338 and collaras 40 required to maintain the desired output torque of assembly 23. Themovement of struts 34-36 concomitant on the movement of the collar 40changes the angular relation of the blades as 31-33 to the axis of shaft338 with a concomitant change in torque developed by the rotor assembly23 with that particular wind velocity. The power train comprised ofblades 31-33, spars 71-73, plate 170, sleeve 339, gears 316, 315, 281and 282 then energize the generator 187. The phase angle or change inphase angle is measured at sensor 317 where generator 187 has analternating current output and the generator output voltage may bemeasured at voltmeter 316 where the generator has a d.c. output. Asignal representative of such measurement is fed back to the controlassembly 305 and is compared with a standard in the memory of thecontrol assembly 3 to initiate or to inhibit further movement of theshaft actuating by disconnecting power to the motor 312 and applying thebrake 311 to shaft 352 when the desired output is obtained. The combinedinputs from the wind velocity measurement apparatus 306 and r.p.m.sensor 307 may also be used to control initiation of movement of theshaft actuating assembly 350 in view of torque measurements. Whenvibration of rotor assembly 23 occurs the r.p.m. sensor is actuated toput into memory the r.p.m. value at which such vibration occurred andthereby set later torque values to avoid those values thereof that wouldprovide such r.p.m. values of assembly 23.

Additionally the output of the generator 187 connects into the sensorassembly 305 and acts therewith to control the motor 312 responsive tothe output which the generator 187 (or 220) provides. Thereby when theoutput of 187 falls below or rises above a certain amount the pitch ofthe rotor blades is controlled by motor 312 for a greater or lesserrotor blade speed (as by increasing or decreasing the distance of thecollar 40 from the plate 170) respectively and a steady generator outputresults.

I claim:
 1. In a windmill comprising a tower and a plurality of airfoilblades, means for controllably adjusting the pitch of the airfoil bladesfrom a feathered position to any run position relative to the directionof the wind, said means comprising:an elongated sleeve member, anactuator shaft coaxially extending through said sleeve, said shaftrotatable with said sleeve and longitudinally moveable relative to saidsleeve, hub means coupled to said sleeve for rotation therewith, aplurality of elongated spar members equal in number to the number ofairfoil blades, each of said spar members having a central portionrotatively in fixed spatial relation to and rotatably supported on saidhub at an angle to the axis of said actuator shaft and a peripheralportion angularly extending from said central portion and fixedlyconnected to one of the blades, said blades extending rearwardly andradially from said hub, said hub located rearward of said tower collarmeans mounted for rotation with said actuator shaft, elongated rigidstrut means pivotally connected at each end respectively to said collarmeans and to the airfoil blade intermediate its ends, and control meansoperatively coupled to said actuator shaft for longitudinally movingsaid shaft and, through said strut means, rotating each of the bladesbeween and including the feathered position and any run position andmoving each of the blades in an arcuate path for changing the dihedralangle of the blades, and spar synchronization means connected betweenthe central portion of each of said spars and said actuator shaftwhereby to maintain the same angular relations between each of said sparmembers.
 2. Apparatus as in claim 1, wherein said spar synchronizationmeans comprises:(a) rigid means slidable longitudinally along saidactuator means, (b) for each of said rotor blades first rigid arm means,a second rigid arm means, a ball joint therebetween, (i) said firstrigid arm means attached at one end thereof to and extendingtransversely to the length of the central portion of the spar of saidrotor blade and, at a second distant end thereof, to said ball joint and(ii) second rigid arm means pivotally connected at one end to saidlongitudinally slidable means on said blade control shaft and, at asecond distant end thereof, to said ball joint.
 3. Apparatus as in claim1 wherein said control means comprises a sensing means sensitive to thetorque developed at said actuator shaft, said sensing means operativelyattached to a motor means including a bearing movable along the lengthof said actuator shaft and operatively connected to said actuator shaft.4. Apparatus as in claim 3 wherein said control means comprises acomparator means operatively connected to said torque sensing means. 5.Apparatus as in claim 1 wherein said control means comprises a brakerelay and a brake, said brake relay operatively connected to saidcontrol means and said brake operatively connected to said actuatorshaft.
 6. Apparatus as in claim 3 wherein such control means comprises avibration sensing means and a memory means, said vibration sensing meansoperatively connected to said memory means and said memory meansoperatively connected to said control means.